Add Bloom.max_mip_count

Author: beicause

crates/bevy_post_process/src/bloom/mod.rs

@@ -361,7 +361,12 @@ fn prepare_bloom_textures(
     for (entity, camera, bloom) in &views {
         if let Some(viewport) = camera.physical_viewport_size {
             // How many times we can halve the resolution minus one so we don't go unnecessarily low
-            let mip_count = bloom.max_mip_dimension.ilog2().max(2) - 1;
+            let mip_count = bloom
+                .max_mip_dimension
+                .ilog2()
+                .min(bloom.max_mip_count)
+                .max(2)
+                - 1;
             let mip_dim_ratio = if viewport.y != 0 && viewport.x != 0 {
                 (bloom.max_mip_dimension as f32 / viewport.as_vec2()).max_element()
             } else {

crates/bevy_post_process/src/bloom/settings.rs

@@ -116,9 +116,13 @@ pub struct Bloom {
     pub composite_mode: BloomCompositeMode,
 
     /// Maximum size of each dimension for the largest mipchain texture used in downscaling/upscaling.
-    /// Lower values can improve performance but reduce quality.
+    /// Lower values can improve performance but result in more aliasing.
     pub max_mip_dimension: u32,
 
+    /// Maximum number of mipmaps to use in downscaling/upscaling (default: [`u32::MAX`]).
+    /// Lower values can improve performance but lose some low frequency contributions.
+    pub max_mip_count: u32,
+
     /// Amount to stretch the bloom on each axis. Artistic control, can be used to emulate
     /// anamorphic blur by using a large x-value. For large values, you may need to increase
     /// [`Bloom::max_mip_dimension`] to reduce sampling artifacts.
@@ -148,6 +152,7 @@ impl Bloom {
         max_mip_dimension: Self::DEFAULT_MAX_MIP_DIMENSION,
         scale: Vec2::ONE,
         high_quality: true,
+        max_mip_count: u32::MAX,
     };
 
     /// Emulates the look of stylized anamorphic bloom, stretched horizontally.
@@ -172,6 +177,7 @@ impl Bloom {
         max_mip_dimension: Self::DEFAULT_MAX_MIP_DIMENSION,
         scale: Vec2::ONE,
         high_quality: true,
+        max_mip_count: u32::MAX,
     };
 
     /// A preset that applies a very strong bloom, and blurs the whole screen.
@@ -188,6 +194,7 @@ impl Bloom {
         max_mip_dimension: Self::DEFAULT_MAX_MIP_DIMENSION,
         scale: Vec2::ONE,
         high_quality: true,
+        max_mip_count: u32::MAX,
     };
 }